When ______ about the possibility that Justin was taken by aliens, Detective Sam Peterson said that there was no hard evidence about this.

I have homework to do. I can’t go fishing with you.

With a lot of difficult problems ______,the newly-elected president is having a hard time.

Hello, this is Jack. May I speak to Tom– Sorry, he isn’t in at the moment. If he _______ back, I’ll ask him to call you back.

The number of road accidents and the deaths _______ those accidents______ greatly over the past year